Effects of aSPIrin Versus Aspirin Plus Low-dose RIvaroxaban on Carotid aTherosclerotic Plaque Inflammation

Prior treatment

• Patients treated with carotid endarterectomy or stent placement
• Need for dual antiplatelet therapy or oral anticoagulant therapy

Other illness

• Stroke in 1 month or any hemorrhagic or lacuna stroke
• Insulin requiring diabetes
• Patients who have experienced critical organ bleeding within 1 year

Lab values

• Severe left ventricular dysfunction (ejection fraction \< 30%)
• Any clinically significant abnormality identified at the screening visit, physical examination, laboratory tests, or electrocardiogram which, in the judgment of the Investigator, would preclude safe completion of the study.
• Hepatic disease or biliary tract obstruction, or significant hepatic enzyme elevation (alanine aminotransferase(ALT) or aspartate aminotransferase(AST) \> 3 times upper limit of normal).

Other

• Contraindications to rivaroxaban or aspirin.
• Unwillingness or inability to comply with the procedures described in this protocol.
• Patient's pregnant or breast-feeding or child-bearing potential.

• Men or women at least 18 years of age inclusive
• Asymptomatic Carotid Artery Disease (diameter stenosis, 20-80%)
• Inclusion criteria for the COMPASS trial (stable Peripheral Artery Disease(PAD); or stable Coronary Artery Disease(CAD) with 1 of age over 65 years, or age \<65 years plus atherosclerosis less than 2 vascular beds or less than 2 additional risk factors)
• FDG Postron Emission Tomography(PET)/Computed tomogrphy(CT) shows hot uptakes at carotid artery (with or without hot uptake at ascending aorta)
• The patient or guardian agrees to the study protocol and the schedule of clinical and FDG Postron Emission Tomography(PET)/Computed tomogrphy(CT) follow-up, and provides informed, written consent, as approved by the Institutional Review Board/Ethical Committee.